Employment of an LED within an electronic device or industry is prevalent day by day. Every electronic device is targeted to produce in compact size. Since the power cost for generating light by the LED is much lower than that of the conventional fluorescent lamps and due to its compact size, the utility of LED within the electronic devices can cause the latter objects to be produced in the compact size too.
Referring to FIG. 1, a fragmentary sectional view of the conventional LED package structure 10 is shown to include a support member 14 disposed on a dielectric member 11, an LED unit 12 disposed within a recess 15 formed in the support member 14, an addressing pattern layer 16 disposed around the recess 15, connecting wires 18a, 18b electrically interconnecting the LED 12 and the pattern layer 16, and an encapsulating body 20 enclosing hermetically the LED 12, the recess 15 in the support member 14 and the inner peripheral portion of the addressing pattern layer 16 except two electrodes 22a, 22b for connection purposes.
Note that the recess 15 in the support member should have sufficient depth in order to receive an individual LED therein. The depth of the recess 15 and the planar elevation of the bottom of the recess 15 are important factors in determining the reliability of LED package structure. Uneven of the bottom surface of the recess 15 in the support member 14 can greatly affect the light emitting stability of the conventional LED package structure.
Since the conventional LED package structure is mass-produced by using an automatic process, it is somewhat difficult to maintain the uniform depth of the recess 15 in the support member 14. Even depth of the recess 15 and evenness of the bottom surface in the recess 15 are two main factors that can greatly affect the light emitting reliability of the conventional LED package structure.
For each of the LED 12, unevenness at the bottom surface of the LED 12 may lead to unstable balance on the support member 14. Moreover, unevenness at the bottom surface in the recess 15 and the LED 12 can result in displacement of the bonding wires 18a, 18b with respect to the LED unit 12, thereby greatly affecting the light emitting reliability of the conventional LED package structure.
Presently, there is urgently in need of a method to remedy the aforesaid two main factors that affect the light emitting reliability of the conventional LED package structure. The support member 14 itself has a relatively small thickness, automatically boring a precise depth in each of the recesses 15 is troublesome. Therefore, it is the main object of the present invention is to find a way improve the light emitting reliability of the conventional LED package structure.